Chronic neurological pain can upend lives. In the wake of the opioid crisis, the use of surgical interventions for chronic pain can benefit a huge population of patients. At Mayo Clinic, our teams are working to develop neurosurgical treatment options for these patients. Rushna P. Ali, M.D., a neurosurgeon at Mayo Clinic in Rochester, Minnesota, leads a webinar discussion about the neurosurgical interventions available.
Subscribe to updates
Neurosciences Physician Update e-Edition
Good afternoon and thank you for joining us for the neurosurgical Interventions for pain webinar. Today, we're very glad to have you with us and we're looking forward to a great discussion this afternoon. I'm pleased to introduce the speaker for today's webinar. Please join me in welcoming Rasna Ali. MD. Doctor Ali is an associate professor and director, the Stereo Tactic and Functional Fellowship in the Department of Neurological Surgery. She's a board certified neurosurgeon with expertise in all saline aspects of stereotactic and functional neurosurgeon including advanced surgical treatments to treat chronic and cancer related pain, facial pain and other neurology. Uh Neuro is sorry, neuralgia, movement disorders, stroke, rehabilitation and recovery, as well as surgical management of epilepsy. Today, she'll be discussing neurosurgical interventions for patients experiencing chronic and cancer related pain doctor. I'll turn it over to you. Thank you for that very kind introduction, Peter. It's a pleasure to be here today and, and talk to the audience about a topic that's uh close to my heart. Um I have no relevant disclosures and what we'll um try to achieve today is identify uh why there is a need for any type of surgical intervention when it comes to managing medically refractory chronic, as well as cancer related pain. Uh We'll go through the indications of uh surgical procedure and outcomes that are associated uh with the various treatment modalities that are available for both chronic and cancer related pain, including neuromodulation as well as lesioning procedures. So, uh the neuromodulation procedures that I'll be talking about include spinal cord stimulation, dorsal root gang and stimulation, peripheral nerve stimulation, uh intrathecal drug delivery as well as motor cortex and deep brain stimulation. Um The uh all of these therapies are aimed at delivering a small amount of electricity or a small amount of intrathecal uh medication that can interrupt the pain circuitry. Uh These are used when we want the therapy to be reversible and titrate the lesioning procedures that I'll focus on today are cordo toy myotomy and dorsal group entry zone lesioning procedures. Uh There are very specific indications uh for these which are limited to a certain subset of patient populations and I'll be going over that as well. And then finally, we'll wrap up with uh the thought process behind having a large multidisciplinary team that can holistically manage a patient uh who is suffering from chronic or cancer related pain. So, why should we care about pain anyway? Uh Well, we should care because chronic pain is endemic in the United States. It has a prevalence of about 30% affects over 23 million adults costs. Uh $635 billion to society. Um And is the most common reason people will see any physician, it leads to an increase in long term opioid use. And as neurosurgeons, we see a fairly large population of, of patients because back pain is the most common subtype of chronic pain that uh people will seek out uh therapy for when we look at cancer pain, uh or pain associated with a known malignancy. Um It is also a very uh predominant issue in those who are already suffering. Um There are about 9 million people that suffer from uh cancer related pain each year and about 50% report inadequate pain control and about a quarter of them um actually die while still in pretty significant pain. So as um as surgeons, we need to do a better job of contributing uh to helping this particularly vulnerable population in, in achieving um appropriate pain control. Um and lessen suffering the pain relief ladder um is what has typically been been used in the past when managing um particularly cancer related pain, where you start off with uh non opioid analgesic like Tylenol Motrin, other nsaids, then you progress to weaker and then stronger opioids. And the top of that ladder is uh the various uh procedures that I discussed. There is an impetus to ensure that it is not uh considered a last tier type of therapy or where um you know, it's, it's sort of an, it's considered a neurosurgical intervention is considered sort of an end of the line type of therapy. Um, because a lot of times by the time these patients reach us, um, they're so debilitated and they're having so many issues and side effects from the multiple medications and opioids that they're on, that they might not even meet surgical candidacy because they reach us uh very late in, in the process. Um So over the, the course of the talk I will be making um you know, um an argument uh associated with supporting data that um after trying an appropriate trial of medical therapy, uh these patients shouldn't wait too long to be referred to a neurosurgical specialist who can help uh with surgical interventions for chronic pain. Now, how do we decide what therapy we uh offer to a patient? Well, it's, it's a very well thought out process and it depends on where in the particular pain pathway we think that the pain is coming from. Um in the, in, in humans, there are three very well defined pain pathways. Uh The first is the lateral pain pathway which is uh responsible for us feeling um sharp uh pain, pain that is associated with a certain sensation. So, you know, you get uh cut by a knife, the pain travels up from the periphery um into the spinal cord synapses in the thalamus and then goes to um the processing area of the brain known as the semantic sensory cortex which tells you that this is a sharp bad pain and you respond accordingly, you pull your hand away. Um If it's uh if it's a situation where you can pull away et cetera, or you um let uh let out any sort of verbalization that um allows other people to intervene and help you. The medial pathway is very interesting because the medial pathway is associated with the suffering that comes along with the sensation of pain. And as you can see, there are different parts of the brain circuitry that are involved, we feel the painful sensation, but then the the neurons that transmit this uh sensation go to different parts of the brain deeper and more superficial. And uh we find that after studying this particular pain pathway, we uh associate the suffering that comes with this pain uh with interventions in this particular pathway. And then the descending pathway um actually starts off in the brain and works its way down through the brain stem and the spinal cord um and actually suppresses um painful sensations. And it's typically um an imbalance of these pain pathways that leads to chronic pain uh becoming a long term issue. Um When we are trying to figure out what part of this pain pathway and which pain pathway we should intervene on. Um We look at what the pain generator is. Uh And typically, we can figure that out if we understand how the pain started. Uh what the features of the pain uh syndrome are. And that informs us on where we should be intervening. So it's typically a three, it's, it's, it's a rather simplistic view. But in most situations, we can boil it down to a three step chain where the first order neuron uh starts uh in the periphery synapses in the dorsal ganglion and then goes up uh to the level of the dorsal horn. The second order neuron will then take it up to the thalamus. And then the third order neuron goes from the thalamus to the the cortex. And um if we're able to localize this pain generator, we can then determine what we need to do and where we need to intervene to best help the patient. If we're intervening at a level below uh where the injury or insult has occurred, we will not be able to break the pain circuitry enough to cause good long term benefit for these patients. And when trying to decide between lesioning, which is a permanently injuring part of this pain pathway depending on where the pain generator is and neuromodulation where we use electricity to disrupt the circuit. There's some characteristics that come into play for lesioning procedures. We typically um uh save it for patients who have a limited life expectancy or who have malignancy related pain. There's easy access to the pain generator or pathway. And uh the reason for doing this is because typically the surgical risk is higher when we try to intervene on 2nd and 3rd order neuron pathways, neuromodulation is um is a good long term solution. So uh works well for patients who have a good long term life expectancy. Um or there's poor access uh to the pain generator or it's diffuse, we aren't able to pinpoint exactly which order neuron the pain is coming from. So we can access a larger circuitry with these uh with these procedures and they typically are involved um with a lower surgical risk profile. So, some uh of the common neuromodulation techniques that we use include spinal cord stimulation, which has been around for a long time. And the theory is that large fibers which carry um normal sensation when stimulated in the in the dorsal part of the spinal cord can suppress the smaller fibers which carry pain sensation. So if you overwhelm the pain sensation in the spinal cord with a bigger more powerful stimulus, it fools your body into thinking that the sensation that you're feeling is not pain but something else. Uh the the principle is um electrodes or wires are placed on top of the spinal cord outside of the dura in the epidural space. And there is a cathode and an A node, the cathode depolarizes or activates the neurons and the A node hyper polarizes or blocks the neurons there. Uh with conventional spinal cord stimulation, there are different parameters that can be changed or modulated based on the patient's response including amplitude, which is how strong the stimulus feels, the pulse width, which is how far the stimulus spreads and the frequency, which is how smooth that sensation is. It is indicated. Uh and FDA approved for uh for chronic pain conditions like post laminectomy syndrome or persistent spinal pain syndrome, non-surgical back pain, complex regional pain syndrome, arachnoiditis, purple neuropathy, and more recently painful diabetic neuropathy. But we also use it often with very good success for neck pain, cervical vertic opathy, plexopathy, uh pain associated with non operative critical limb ischemia, pain, and non operative angina pain. These are patients who can no longer have multiple revascularization procedures done and the goal is not to help with their circulation but just be able to manage the pain that is associated with these conditions for cancer pain, spinal cord stimulation is indicated to treat uh neuropathic cancer pain that can occur when a tumor is involving um larger nerves or a plexus of nerves. Um as well as uh helping with radiation or chemotherapy induced pain. Uh smaller trials have been conducted which have shown good results where uh most patients receive at least 50% or more improvement in their pain. Uh Some common complications include uh spinal fluid leaks, uh infections at about 5%. And then hardware issues like the wires moving out of place or fracturing leads anywhere from 5 to 10%. The way the surgery is done is um it can be done both as a percutaneous needle approach or through an open laminotomy after making an incision um in the middle of the, in the middle of the back where we place the wires depends on where the pain is located. And we use dermatomal anatomy and physiology to inform us on uh the level at which the spinal cord should be stimulated. In order to get patients the best relief we use uh intraoperative X ray to make sure that we are in the correct region. The the wires are placed in the epidural space, which is the space uh between the lining of the, the spinal cord and the bone. Uh With all of these neuromodulation procedures, we have to do a trial before doing a permanent implant because it doesn't work for everybody. And during the trial, what we're looking for is a 50% or more improvement in in the painful symptoms. And if we achieve that goal, then we can proceed with a permanent implantation of the device. If the trial is unsuccessful or the patients don't obtain that degree of relief, then we remove the electrodes or we remove the wires and we don't proceed with a permanent implant because it, it wouldn't make sense to implant hardware in somebody uh where it's unlikely to make a meaningful difference to them. Now, in addition to conventional spinal cord stimulation that I discussed a few slides ago, we now have a lot of different waveforms um or software technology that can be tried. Um There are several open loop systems which use conventional or tonic square wave uh stimulation patterns. Um There are waveforms that can mimic the way our thalamus fires and it can match that frequency with the help of burst stimulation. Uh There's five frequency stimulation upwards of 10 kilohertz. And there is a multi waveform stimulation that not only stimulates uh neurons but also stimulates the glial cells and um helps uh to improve the the neuro inflammatory profile um in the area. And uh is thought to play a big role in uh in the way these therapies help patients. We now also have closed loop systems available which can respond and change the amount of stimulation that is being delivered in in an automatic um um artificial intelligence based algorithm uh currently because this technology is very new. It's only responding to um um the the strength of the response by the spinal cords. Remember it stimulates or depolarizes certain uh fibers in the spinal cord. These systems can record that response and then change the next output accordingly. So, you know, some similar complain, uh some complaints that we get from patients with small course stimulation is um as they move around um the the amount of stimulation they feel changes because the amount of spinal fluid between the device and their actual spinal cord changes with positions. This therapy allows to make minute adjustments based on those positional changes so that patients can get a more smoother delivery of current. There is a good evidence uh supporting each of these new uh paradigms in the form of multiple uh randomized control studies that have been conducted for high frequency uh stimulation. Um The high frequency paradigm was compared with traditional spinal cord stimulation and was found to be superior. Uh similarly for the birth stimulation which mimics uh the thalamic firing. Um It it also showed improved uh uh pain control both in back and leg pain. When compared to traditional or conventional spinal cord stimulation, the differential target multiplex uh stimulation which focuses on uh activating not just neurons but also the surrounding glial structures. Uh Also when compared with conventional stimulation was uh was associated with better outcomes both for back and leg pain. Um And lastly, the closed loop stimulation showed uh that the, the initial trial um where uh closed loop stimulation was compared with open loop stimulation showed uh more patients achieving more than 50% improvement in their pain in the closed loop group. And uh a subsequent trial um showed similar uh results at uh at two years as well when it comes to cancer pain. Um spinal cord stimulation has been shown to be effective both in the short term and in the long term um when it is used in the appropriately selected patients, which are patients who have uh neuropathic pain associated with their, with their cancer or subsequent cancer related therapies and time to intervention matters. Um, kind of going back to that, uh, LA that I was discussing initially, we should not consider these therapies to be end of the line. What does that mean you, that means that patients should certainly try, um, appropriately selected medications, physical therapy, pain interventions such as nerve blocks, epidural injections, facet injections based on what type of pain they're having and what the location of that pain is. Uh, but if after a trial of appropriately selected medications and therapy, if within 3 to 6 months, uh you're not seeing significant improvement. That is the time to refer these patients uh over for, for more involved therapy if they're interested. Simply because we find that the longer patients have chronic medically refractory pain, the, the success rate for any neuromodulation and intervention falls steeply probably because chronic pain rewires our circuitry and ends up becoming much harder to treat any anytime we try to interrupt that circuitry with, uh with external stimulation. So, referring these patients, once they've had an appropriate trial of medical therapy and physical therapy for 3 to 6 months is, is very appropriate. Um, once again, uh, something to remember is that if they've had a spinal cord stimulation trial, but didn't do well with it, that doesn't mean that if their pain has progressed. Um And especially now, since technology has progressed, that we can't uh try a different modality if they have failed a percutaneous approach, then we can do an open approach with a paddle lead uh that can provide uh a more dense and focused area of stimulation. So certainly, um if patients have failed to trial spinal cord stimulation in the past, doesn't mean that they won't be um candidates. Uh currently, especially if those trials occurred a few years ago because technology has significantly um changed and uh progressed dorsal who gaining and stimulation also became recently available. Um And it is indicated and works really well for pain that is more localized in uh in distribution. So um targeting certain anatomical areas that are difficult to treat with spinal cord stimulation, like just pin the pelvis or the groin or the knee or the foot and the ankle. Um These devices work phenomenally. They can be used either with or without paraesthesias. Uh The lead is placed along the dorsal root ganglion itself. Uh And because there's less spinal fluid in that area, there's less postural change um that's associated with the stimulation. Um And um it is performed as an outpatient um percutaneous procedure which the patients tolerate really well. Um There's once again good uh high level level one data to recommend its use when this type of device was compared with traditional spinal cord stimulation. Um it produced better results at improving focal like pain. Now, remember this is comparing DRG stimulation to traditional spinal cord stimulation, not the newer paradigms that we just talked about. So, um it's an area of ongoing study, if the newer uh parameters that are associated with spinal cord stimulation now might produce equivalent results. But uh we typically tend to favor DRG stimulation when the pain is fairly focal. As mentioned, this is a percutaneous procedure. Uh We access the epidural space through a needle. Uh We pass the wire along the dorsal root ganglion, we make a hairpin relief, strain relief loop. So the wire doesn't get pulled out of place easily. Uh Once again, we have to do a trial and if the trial is successful, we, we do a permanent implant. And with this current system that's available, we can put four leads in in at one time. And in those patients who are not candidates for a percutaneous uh um procedure, either they've had prior surgery that makes access harder or they have some local arthritis in the area that doesn't allow us to put uh the dorsal root Gian stimulator in open uh approaches have been uh tried and attempted. We typically try not to do this uh because that's not what the device is on label for, but uh certainly something that can be done successfully pumps or intrathecal drug uh delivery therapy is also a very, very powerful tool. Um There are two main sort of categories that this is used for uh Baclofen. Intrathecal baclofen is used for spasticity that's associated spinal cord injury, stroke, cerebral palsy traumatic brain injury. It can be a very, very life changing therapy for patients who have a lot of spasticity that's medically refractory. Uh and then morphine or ziconotide is FDA approved for treatment of chronic pain that is either related to cancer, which is the the most common indication to use these pain pumps in patients with cancer related pain who have a life expectancy um of more than 3 to 6 months. Uh chronic neuropathic pain, diffused, visceral pain all responds well to, to this therapy. Once again, we have to do a trial. The trial here is through, um, an injection done through a lumbar puncture. Um And after that, the response is measured by testing either the pain scores or the level of spasticity. Um, if the patients have a 50% or more improvement in their symptoms, then we proceed with a permanent implant. Once again, it's a simple outpatient surgery. Um, the pumps can then be transcutaneous filled when they, when they're about to empty out. Um, they can be programmed wirelessly where the dose delivered can be changed where the frequency uh can be changed. Uh, the medications can be switched out. Let's say somebody isn't responding to morphine. You can in the office, transcutaneous change the medication and try ziconotide instead without having to redo another surgery. Um, and it's, it's a, it's a, it's a good therapy both for cancer related pain and chronic pain where the, the pack guidelines, um, Uh The more recently updated guidelines are recommending this therapy as a category one recommendation for both localized and diffused cancer related pain. Um Patient selection, as I mentioned, patients with advanced stage cancer life expectancy of three months or more who have a pain score of five or more and have been tried on appropriate doses of opioids and are simply not responding. And we have good data to suggest that it works really well. It improves pain reduction when compared to continued medical therapy and is associated with fewer side effects, um such as fatigue, impotence, pruritis, um grogginess, reduced consciousness, all of these side effects are lower if you're delivering these medications intra particularly as opposed to, to orally. But as with any surgical therapy, it comes with um complications again, thankfully, as the technology and our um skill at implanting these devices has gotten better, so have the rates of complication but things to look out for would be infection. Uh seroma in the pump pocket, spinal fluid leaks, um catheter malfunction, loss of efficacy. And then based on the medications that are being used, overdose and withdrawal symptoms, um should be recognized and managed appropriately as well. And it's cost effective, you know, a lot of time we, we deal with nihilism when it comes to treating chronic or cancer related pain because you know, why would you go ahead and implant an expensive device in somebody um who might not be alive for a very long time. Well, it has been shown that this therapy is indeed cost effective where um after the pump was implanted and patients who had more than three months to live, it uh saved uh over $3000 per episode. So these patients were making fewer visits to the emergency department. Their um medical management costs were lower. Their quality of life was improved. Peripheral nerve stimulation is another modality to help manage chronic pain. Typically not something we use for for cancer related pain, but this is more for chronic pain. Um uh peripheral nerve stimulation, targeting um idle to mel branch nerves um or placed subcutaneously in an area that is uh painful, uh uh due to neuropathic pain or direct placement into the multi FTS muscles. In patients with chronic low back pain has has shown uh success. Similarly, patients who have um headaches, atypical facial pain or occipital neuralgia that is not responding to medications can have these wires implanted subcutaneously, which means we make a very small little puncture and then thread the wires um along um their their pain distributions. We do a trial. If this trial is successful, then these wires are tunneled down and hooked up to a generator that's as under the skin. But these can be very, very effi active therapies for those who are dealing with the uh chronic headaches, migraines, occipital neuralgia, and other type of atypical facial pains that are, that are not responsive to medical therapy or facial pain. That is not the typical trigeminal neuralgia pain that can be addressed with the more traditional approaches. And lastly, intracranial neuromodulation is something that is reserved for central neuropathic pain patients or chronic pain patients who have pain because of a spinal cord injury, a stroke, trauma, or traumatic brain injury, um multiple sclerosis and some very resistant trigeminal neuropathies. Um evidence suggests that there's about um um an imp improve of about 50% of pain symptoms and 60% of patients. So, not, not the greatest results but still something very valuable for patients who have this very refractory type of central neuropathic pain. Multiple targets have been explored. The best evidence exists for motor cortex stimulation, an thalamic stimulation. Currently, although inter singular uh and um other parts of the pain circuitry are being uh studied for its uh its role in managing central neuropathic pain. Now, those were sort of the the workhorses of the various neuromodulation procedures that we have available to us at this point in time to treat both cancer. Um and some only for for chronic neuropathic pain lesion procedures come into place where we are either dealing with uh cancer related pain, where life expectancy is limited or uh where uh long term benefit can be achieved with a limited risk profile. So dorsal root entry zone lesioning is is one such procedure that can be life changing for patients who have pain, uh particularly pain associated with brachial plexus or lumbar plexus avulsion injuries where uh the nerve roots have basically been disrupted or pulled out or injured. And they had this diffuse pain in their arm or their leg associated with this injury. It's also used in patients with spinal cord injury who have persistent neuropathic pain, um, or pain that develops after a peripheral nerve lesion, spasticity associated pain and less frequently a pain associated with the malignancy that involves the racial plexus or the lumbar plexus. Um It's a technique where the goal is the destruction of the most superficial layer of the, of the dorsal horn, which is where the nerves come in and uh and take a deeper dive into the center portion of the spinal cord. It provides unilateral uh pain relief localized to the level of the lesioning. So we have to determine exactly which derma toes are involved and, and, and lesion those and there's good um outcomes. Although most of the uh large studies have looked at uh predominantly uh pain associated with racial plexus injuries. Uh some studies have included uh pain due to multiple other etiologies and uh based on that the the results are pretty, pretty reasonable where there is about more than 75% relief in half or more of the patients who are included in these studies. Complications can certainly occur because this is very high stakes real estate we are going in in a very small part of the spinal cord and trying to uh trying to lesion, uh a small portion of it. So, if you see here, this is where we want to make the lesion. But right next to it are areas that control balance right next to it over here are areas that control movement. Um And the deeper you go, then we get areas and centers that control bowel bladder function as well. So all things that we need to be very, very cognizant about. Um Cordo toy is a procedure where we uh injure um part of the spinal cord uh that is reserved for patients who have cancer related pain. Um, leaching procedures have been performed for a very long time. Um In this particular procedure, we're uh destroying the lateral spinal thalamic tract, which is responsible for conducting the pain sensation from the periphery all the way up to the thalamus and the somatosensory cortex in the brain. And this disrupts pain and temperature sensation from the opposite side of the body that is below the level of the lesion. So we save it for intractable unilateral somatic pain or no susceptive pain. Uh patients who have bilateral pain, midline pain or pain above uh the level of C five in the cervical spine are not candidates for this. The way we do the surgery is, uh uh traditionally, we would do it uh do an open approach where we would do a couple of levels of laminectomy release the dead ta ligaments that are tethering the upper spinal cord um to the sides of the spinal canal, rotate the spinal cord and make an incision or a lesion or burn uh just in front of where the spinal cord was attached to the spinal column. Um because we know that's where the based on anatomical studies, that's where the, where this particular tract lives. And as long as we're staying um in front of the dentate ligament right over here, that is tethering the, the spinal cord to the inner portion of the spinal canal will be safe and will only be disrupting the spinal thalamic tract and and not uh causing any major side effects. Um As you can imagine, um it's not a surgery that's performed commonly because um it's reserved for AAA specific group of patients. But in the smaller studies that have uh been performed, it does lead to significant pain improvement in, I mean, the majority of these patients. Uh one reason that we reserve it for patients with a limited life expectancy is if you follow these patients out, uh you know, at about the two year mark, you start to see some pain, uh recurrence occur because the the tracks are starting to repair themselves. Um more recently, um a safer um and quicker approach to this um has been developed which is a percutaneous way of conducting the, the same type of lesioning procedure where uh we perform a myelogram and then using fluoroscopic techniques, uh we insert a small lesioning probe into the spinal cord instead of um opening things up and uh visualizing it directly. We visualize and use uh myelography uh to guide this and make a steer tactic lesion. Um Instead, uh again, very good results associated with it. And the complications that do occur uh tend to be mostly temporary. And lastly, myotomy are used when um we are dealing with cancer pain, patients who have diffused, visceral pain or midline pain. What this basically does is uh it disrupts the the pathway where the pain fibers are crossing and thus helps with any pain that is associated with the primarily being present in the midline or in deep in the viscera because the visceral fibers cross um in this uh in this comic area as well that is being transected and disrupted. Uh The way we perform the surgery is we do based on where the pain is. We do a multilevel laminectomy. We identify the midpoint of the spinal cord dorsally. Um After finding the midpoint between the two dorsal root entry zone, um areas, there's typically a vein running along the center that is mobilized. And then either with a knife or a lesioning probe, we uh essentially um make an incision in the midline and go all the way to the front. Uh so that we are disrupting all of these fibers that are crossing in the midline. It's associated with good uh pain relief in patients. However, uh the side effect profile of complication profile isn't insignificant. And a lot of these patients exhibit uh new weakness or urinary um issues uh difficulty with proprioception, et cetera, which led to the development of the Punt take myotomy where a smaller lesion is made. And there is uh it's, it's a very focused uh lesion. Um where if you have pain in the upper abdominal viscera, we limit the lesion to T 34. If the pain is limited to the pelvic viscera, then we make a small lesion at T six to T eight. And compared to the Compal myelotomy that we looked at the disruption is minimal. It's not as long and it's not as deep and it still works really well. Uh We can make a smaller opening and either with the angio cat or lesioning probe, we go in uh to about a five millimeter depth. It's something that we can measure on, on presurgical MRI S as well. So we can be quite precise and essentially rotate this. So we're making a lesion in all four quadrants in this area. But once again, it's a focal lesion, it's less than a millimeter um in width and uh causes less disruption and therefore, leads to a lower risk profile while still being able to achieve good um surgical outcomes. But none of these surgeries um would produce good reproducible and successful long term benefit if it were not for the efforts of a large multidisciplinary team. You know, a neurosurgeon is just one part of this entire uh spectrum. Uh It is very, very important that it's a large group of experts who are um part of the decision making that helps us determine who is a good candidate for any of these surgeries and why. So servicess to be involved should include oncology, neurology, pain management, palliative care, neuropsych, uh pain medicine, and rehab, a nurse, Navigator, a care management specialist. Um so that we can look at each and every individual patient and determine their candidacy. Evaluate specific risks and benefits, determine the surgical target and the and the surgical approach make sure we are optimizing them pre surgically and most importantly, track our post surgical outcomes to make sure that we're doing the right thing and having the necessary and appropriate impact. So, in conclusion, um collaboration instead of working in silos is what's going to help us uh bridge this gap and help this very vulnerable patient population by offering them the appropriate therapies. Um The optimal intervention should be determined by a large multidisciplinary team of experts, uh like the ones we have at Mayo Clinic and what it all boils down to is the patient selection is crucial. And if we make it a patient centric approach, we, we are most likely to achieve the best outcomes. Thank you. And I'll take any questions. Well, Doctor Ali, thank you very much. For a wonderful presentation. This afternoon, we have a handful of questions that have come in. Uh So I'll go through them one by one and we'll get through as many of them as uh as time allows. The first question that came in is what is the value of spinal cord stimulation and peripheral neuropathies which are not painful, uh just para parasthesia, numbness, tingling, et cetera. So, um it's, it's, it's a, it's a very timely question because currently a clinical trial is being designed to look at specifically that to see if spinal cord stimulation uh makes a difference in the in the sensory profile of these patients with purple neuropathies because there is some anecdotal evidence to suggest that in patients who had a painful neuropathy uh and had a spinal cord stimulator implanted. Um One of the secondary um outcomes that were seen was not only an improvement in their pain but their uh sensory profile, but because it was never a primary outcome, it wasn't studied in depth. It wasn't um you know, measured very, very objectively preoperatively or postoperatively. So, there is work underway to study the impact of small cord stimulation only on the sensory um effects in in purple sensory neuropathy that are not painful. So I would say stay tuned and let's see what the data tells us right now. Uh It's mostly just anecdotal which seems to suggest that they may improve the sensory profile, but it's only been studied in patients who have a painful sensory neuropathy. Ok. Well, thank you very much for that answer. Uh The next question that came in is do you have any experience with Midline myelotomy? For example, cancer pain? Uh Yes. So um if we go back, um Midline myotomy um are used uh typically for either Midline or um pain that is associated with the visceral pain that can happen with diffuse cancer, either in the abdomen or or uh pelvic area. And the purposely selected patients, it, it can work really well. OK. The next question is if my patient is still receiving chemotherapy or radiation, are they a candidate for these surgical pain interventions? So, um the short answer is yes, they would be a candidate for lesioning procedures because the time to heal depending once again on uh what type of lesioning procedure we're doing um uh is possible. However, we do want them to have completed or be in a little bit of a reprieve from their chemo and radiation um Before we do a hardware implant because chemo ongoing chemo and radiation significantly incr increases their uh infection risk. So if there is, let's say um a 6 to 8 week period where their uh chemo and radiation can or will be held for whatever reason, that is the optimal time to do this. So they have um a good uh 6 to 8 weeks to heal from their intervention. OK. The next question here writes some of my patients with colorectal cancer experience lower back pain due to the position of the tumor. Uh some so severe, they are unable to lay in a single position for radiation treatment. Without severe pain, would spinal cord stimulation be an option uh to help for them to help them undergo the rest of their treatment plan. Um So in that situation, because the pain is actually referred pain from uh the viscera that is then being referred to the low back area. Actually, intrathecal drug delivery systems would be a better solution for these patients. So a pain pump where they can undergo a quick trial uh through an LP. And if they respond, um get a permanent implant done would be a more um sort of we'll get you more bang for your buck than spinal cord stimulator because this is referred pain from the viser, not primarily low back pain. Thank you. Uh The next question is, are these interventions more for patients now in remission? So, um for those patients who we have both options, right? So we reserve the lesioning procedures for patients who have a limited life expectancy um because we don't want to implant hardware and have them go through multiple trials, et cetera. Um when, when they have a limited life expectancy. But um the neuromodulation options that exist um exist for patients who have, they don't necessarily need to be in remission per se, but we should have an idea of whether or not their life expectancy is going to be three months or more. And if the answer to that is yes, then they would certainly be considered uh for neuromodulation procedures. But if they have a, if they have, you know, ongoing severe pain with, uh, you know, disease, that is certainly not in remission with a limited life expectancy, then lesioning procedures can certainly be considered for them. Thank you. We still have some questions. So, if you have a few, um, how do I know my patient is a good candidate for these? Oh, so, um, that would be a very, very lengthy answer. And I would say, um, some like a basic rule of thumb would be, um, does your patient have chronic or cancer related pain? Um, have they tried appropriate medications and physical therapy? And uh, you know, some intermittent pain interventions depending on, you know, what type of pain they have because, uh, some of these, uh, you can do some pain interventions for like, you know, try a nerve block or an epidural steroid et cetera. But for some, um, there really aren't very many uh interventional pain options. Um, so again, it would depend on the type of pain, the etiology of the pain. But if they've tried medications, they've tried physical therapy, they've tried any indicated pain interventions. And within 3 to 6 months, you're not seeing a meaningful improvement in their pain symptoms and their pain scores are still consistently five or more. Then I would say refer them to a specialist and let them make the assessment. Um because there are a lot of nuances to this that we do need to consider. Um based on the type of pain, the location, the pain generator, their response to certain therapy, um, the presence of a certain disease, phenotype, et cetera can play, play into our decision. But for any referring providers, that's, that's what I would recommend. Ok, thank you. And what is the optimal time for pain intervention for a patient is time to intervene in intervention important for all the different intervention methods or just for spinal cord stimulation for all intervention methods. Uh because chronic pain, uh regardless of where in the three step order neuron chain, we're dealing with um changes the pain circuitry and as it changes, it becomes more resistant to any intervention. So timed intervention matters for, for all neuromodulation interventions. And what is the optimal time for pain intervention for a patient? Um I would say if they've tried medications, physical therapy and any indicated pain interventions for at least 3 to 6 months and you have not noted any significant improvement in their symptoms. That's the time to refer. Ok, thank you. And how long does a referral and evaluation process typically take? Um Again, it, it depends on what type of pain they have, what therapy we're considering. But typically at the Mayo clinic, once we receive a referral, it's routed to the appropriate surgeon. We review it uh within a few days and make the determination on whether or not this is somebody who is appropriate to be seen. Uh We certainly can make sure that we prioritize patients who have a more urgent need. Uh But we try and get them in um as, as quickly as possible and then we take care of any um associated imaging or further testing, um, et cetera that might be needed prior to us intervening on them. Ok. And then the final question that came in and we may have partially answered this previously was how long should I have my patient manage their pain with medication before considering them for a referral for surgical intervention? Yeah. So 3 to 6 months again, appropriate style of medications, physical therapy, et cetera. And if you're not seeing improvement, then that's the time to do it. Ok. Well, Doctor Ali, that is the, the end of the questions that we received for the program. We do appreciate your time today and your insight and appreciate you sharing your time with us. Of course. Thank you for having me. Thank you and to all of you who are watching today, we thank you for joining us today. We hope that you found the presentation informative and we look forward to seeing you next time. Thank you for your time and we wish you all a very, very nice day.
